The present invention relates to steel, more particularly to methods for evaluating ballistic properties of steel materials and bodies.
The ballistic perforation of steel targets is a complex process that includes global dynamic deformation, local instable adiabatic shear deformation, strain hardening, phase transformation, and various separation and failure modes. See the following references, each of which is incorporated herein by reference: M. E. Backman and W. Goldsmith: Int. J. Eng. Sci., 1978, 9, 1-99; T. BØrvik, J. R. Leinum, J. K. Solberg, O. S. Hopperstad and M. Langseth: Int. J. Impact Eng., 2001, 25 553-572; Y. B. Xu, J. H. Zhang, Y. L. Bai and M. A. Meyers: Metall. Trans. 2008, 39A, 811-843.
Targets behave differently depending on the configuration and characteristics of the target and threat, as well as the ballistic impact velocity and striking angle. See the following references, each of which is incorporated herein by reference: T. BØrvik, J. R. Leinum, J. K. Solberg, O. S. Hopperstad and M. Langseth: Int. J. Impact Eng., 2001, 25 553-572; T. BØrvik, M. Langeth, O. S. Hopperstad and K. A. Malo: Int. J. of Impact Eng., 2002, 27, 19-35; S. Dey, T. BØrvik, O. S. Hopperstad, J. R. Leinum and M. Langseth: Int. J. Impact Eng., 2004, 30, 1005-1038.
Accordingly, there is no universal relationship among microstructure, conventional mechanical properties, and ballistic resistance V50. For example, higher hardness enhances the resistance of steel targets to armor piercing (AP) ballistic penetration, but weakens their resistance to fragment simulation projectile (FSP) ballistic perforation. Since microstructure, conventional mechanical properties, and ballistic resistance V50 cannot be predictably reconciled, the development of new steels of superior ballistic resistance remains a difficult task.
The following references, each of which is incorporated herein by reference, are informative on ballistic and other properties of steel: T. BØrvik, S. Dey and A. H. Clausen: Int. J. Impact Eng., 2009, 36, 948-964; J. F. Chinella and M. G. H. Wells: ARL-RP-64, US, February 2003; S. N. Dikshit, V. V. Kutumbarao and G. Sundararjan: Int. J. Impact Eng., 1995, 16, 293-320; W. Gooch, M. Burkins and D. Mackenzie: 22nd Int. Symposium on Ballistics, Vancouver, Canada, 2005; S. J. Manganello and K. H. Abbott: J. of Materials, 1972, 231-239; D. D. Showalter, W. A. Gooch, M. S. Burkins, J. S. Montgomery and R. Squillacioti: AMMTIAC, 2010, Vol. 4, No. 4, 2010; D. D. Showalter, W. A. Gooch, M. S. Burkins and R. Stockman Koch: ARL-TR-4632, US, 2008; D. D. Showalter, W. A. Gooch, M. S. Burkins, V. Thorn, S. Cimpoeru and R. Barnett: ARL-RP-181, US, 2007; D. D. Showalter, W. A. Gooch, M. Burskins, J. Montgomery and R. Squillacioti: ARL-TR-4997, 2009.